Abstract: Methods and systems for imaging internal tissues within a body are provided. In one aspect, a method for imaging an internal tissue of a body is provided. The method includes inserting an image gathering portion of a flexible endoscope into the body. The image gathering portion is coupled to a sensor configured to sense motion of the image gathering portion with respect to fewer than six degrees of freedom. A tracking signal indicative of motion of the image gathering portion is generated using the sensor. The tracking signal is processed in conjunction with supplemental data of motion of the image gathering portion to determine a spatial disposition of the image gathering portion within the body. In many embodiments, the method includes collecting a tissue sample from the internal tissue.

Abstract: A method and apparatus for obtaining force versus deformation data for tissue in vivo includes a displacement system that cycles an anatomical member, for example, a foot, repeatedly through a loading/unloading cycle while using a gated imaging procedure such as magnetic resonance imaging to obtain the deformation response of tissues in the foot. The imaging is conducted during the loading/unloading cycle, such that a rate-dependent deformation response is imaged.

Abstract: An object is tracked among a plurality of image frames. In an initial frame an operator selects an object. The object is distinguished from the remaining background portion of the image to yield a background and a foreground. A model of the background is used and updated in subsequent frames. A model of the foreground is used and updated in the subsequent frames. Pixels in subsequent frames are classified as belonging to the background or the foreground. In subsequent frames, decisions are made, including: which pixels do not belong to the background; which pixels in the foreground are to be updated; which pixels in the background were observed incorrectly in the current frame; and which background pixels are being observed for the first time. In addition, mask filtering is performed to correct errors, eliminate small islands and maintain spatial and temporal coherency of a foreground mask.

Abstract: Intraoperative ultrasound (US) is integrated with stereotactic systems, where a system interactively registers two-dimensional (2D) US and three-dimensional (3D) magnetic resonance (MR) images. The registration is based on tracking a US probe with a bC magnetic position sensor. A transformation algorithm is performed to transform coordinates of points between two different spaces, where MR and US image spaces are independently registered with the position sensor space and where coordinate points can be registered between the MR and US spaces. A calibration procedure can be performed, and a phantom can be used to determine and analyze registration errors. The registered MR images can reconstructed using either zero-order or first-order interpolation.

Abstract: An object is tracked among a plurality of image frames. In an initial frame an operator selects an object. The object is distinguished from the remaining background portion of the image to yield a background and a foreground. A model of the background is used and updated in subsequent frames. A model of the foreground is used and updated in the subsequent frames. Pixels in subsequent frames are classified as belonging to the background or the foreground. In subsequent frames, decisions are made, including: which pixels do not belong to the background; which pixels in the foreground are to be updated; which pixels in the background were observed incorrectly in the current frame; and which background pixels are being observed for the first time. In addition, mask filtering is performed to correct errors, eliminate small islands and maintain spatial and temporal coherency of a foreground mask.

Abstract: A device to detect the location of a plurality of magnets uses a plurality of magnetic sensors, having sensor elements arranged in a known fashion. Each sensor element senses the magnetic field strength generated by each of the plurality of magnets and provides data indicative of the direction of the magnets in a three-dimensional space. The device uses fundamental equations for electricity and magnetism that relate the measured magnetic field strength to the location and strength of the magnetic dipole for each of the plurality of magnets. The device may use an iterative process to determine the actual location and orientation of each magnet. An initial estimation of the location and orientation of each magnet results in the generation of predicted magnetic field values. The predicted magnetic field values are compared with the actual measured values provided by the magnetic sensors.

Abstract: A device to detect the location of a magnet coupled to an indwelling medical device within a patient uses three or more sets of magnetic sensors each having sensor elements arranged in a known fashion. Each sensor element senses the magnetic field strength generated by the magnet and provides data indicative of the direction of the magnet in a three-dimensional space. The device uses findamental equations for electricity and magnetism that relate measured magnetic field strength and magnetic field gradient to the location and strength of a magnetic dipole. The device uses an iterative process to determine the actual location and orientation of the magnet. An initial estimate of the location and orientation of the magnet results in the generation of predicted magnetic field values. The predicted magnetic field values are compared with the actual measured values provided by the magnetic sensors.

Abstract: A device to detect the location of a magnet coupled to an indwelling medical device within a patient uses three or more sets of magnetic sensors each having sensor elements arranged in a known fashion. Each sensor element senses the magnetic field strength generated by the magnet and provides data indicative of the direction of the magnet in a three-dimensional space. The device uses fundamental equations for electricity and magnetism that relate measured magnetic field strength and magnetic field gradient to the location and strength of a magnetic dipole. The device uses an iterative process to determine the actual location and orientation of the magnet. An initial estimate of the location and orientation of the magnet results in the generation of predicted magnetic field values. The predicted magnetic field values are compared with the actual measured values provided by the magnetic sensors.

Abstract: A device to detect the location of a magnet coupled to an indwelling medical device within a patient uses three or more sets of magnetic sensors each having sensor elements arranged in a known fashion. Each sensor element senses the magnetic field strength generated by the magnet and provides data indicative of the direction of the magnet in a three-dimensional space. The device uses fundamental equations for electricity and magnetism that relate measured magnetic field strength and magnetic field gradient to the location and strength of a magnetic dipole. The device uses an iterative process to determine the actual location and orientation of the magnet. An initial estimate of the location and orientation of the magnet results in the generation of predicted magnetic field values. The predicted magnetic field values are compared with the actual measured values provided by the magnetic sensors.

Abstract: An ultrasound system automatically measures fetal head size from ultrasound images. An ultrasound image of the fetal head is detected. A radial maxima point is identified on each of a plurality of radii extending from a substantially common vertex point within the fetal head image. Each radial maxima point corresponds to an ultrasound sample along its corresponding radius, and has a maximum ultrasound echo strength. A first curve is defined from the radial maxima points. The remaining unfiltered radial maxima points are fit to a second curve, and the second curve is the detected curved boundary. The detected curve boundary is modified to define an initial fetal head boundary. An inner fetal head boundary and outer fetal head boundary are derived from the initial fetal head boundary and a predetermined fetal skull thickness, and fetal head size is computed from the inner fetal head boundary and the outer fetal head boundary.